Error - buoyantBoussinesqSimpleFoam Solver
 

Hi!

I am new to OpenFOAM and I don't know how to resolve this problem: (I did the mesh in Salome).

Time = 3

DILUPBiCG: Solving for Ux, Initial residual = 0.586599, Final residual = 0.00342578, No Iterations 2
DILUPBiCG: Solving for Uy, Initial residual = 0.123037, Final residual = 0.000729083, No Iterations 2
DILUPBiCG: Solving for Uz, Initial residual = 0.715719, Final residual = 0.00748276, No Iterations 2
DILUPBiCG: Solving for T, Initial residual = 1.84479e-08, Final residual = 1.84479e-08, No Iterations 0
DICPCG: Solving for p_rgh, Initial residual = 0.999996, Final residual = 475.492, No Iterations 1001
time step continuity errors : sum local = 3.16764e+17, global = -8.23715e+13, cumulative = -8.23715e+13
DILUPBiCG: Solving for epsilon, Initial residual = 1, Final residual = 0.040937, No Iterations 21
DILUPBiCG: Solving for k, Initial residual = 0.00305874, Final residual = 1.17067e-08, No Iterations 1
bounding k, min: -3183.13 max: 1.51602e+26 average: 1.03354e+21
ExecutionTime = 30 s ClockTime = 30 s

Time = 4

DILUPBiCG: Solving for Ux, Initial residual = 4.73418e-05, Final residual = 9.99871e-06, No Iterations 7
DILUPBiCG: Solving for Uy, Initial residual = 6.06685e-06, Final residual = 6.06685e-06, No Iterations 0
DILUPBiCG: Solving for Uz, Initial residual = 6.1559e-06, Final residual = 6.1559e-06, No Iterations 0
DILUPBiCG: Solving for T, Initial residual = 4.68967e-08, Final residual = 4.68967e-08, No Iterations 0
#0 Foam::error::printStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 in "/lib/x86_64-linux-gnu/libc.so.6"
#3 Foam::divide(Foam::Field<double>&, double const&, Foam::UList<double> const&) at ??:?
#4 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam::operator/<Foam::fvPatchField, Foam::volMesh>(Foam::dimensioned<double> const&, Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > const&) at ??:?
#5
at ??:?
#6 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#7
at ??:?
Floating point exception (core dumped)

Thanks.

Hi,

there's not much information about your case, so according to

it's diverging.

To answer you question "why it's diverging?", one needs to know a little bit more about your case: checkMesh output, initial conditions, boundary conditions.

Hi,

it seems you have a boundary condition problem. Look to your p iteration... more than 1001.

Bye
Thomas

Hi!

Thanks for your replies.

Here's the output from checkMesh:

/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.3.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Build : 2.3.0-f5222ca19ce6
Exec : checkMesh
Date : Oct 23 2014
Time : 12:01:17
Host : "psci-ThinkPad-T440s"
PID : 3751
Case : /home/psci/OpenFOAM/psci-2.3.0/run/barn_4pigs_22Oct
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Disallowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create polyMesh for time = 0

Time = 0

Mesh stats
points: 44271
faces: 489678
internal faces: 478946
cells: 242156
faces per cell: 4
boundary patches: 9
point zones: 0
face zones: 0
cell zones: 0

Overall number of cells of each type:
hexahedra: 0
prisms: 0
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 242156
polyhedra: 0

Checking topology...
Boundary definition OK.
Cell to face addressing OK.
Point usage OK.
Upper triangular ordering OK.
Face vertices OK.
*Number of regions: 5
The mesh has multiple regions which are not connected by any face.
<<Writing region information to "0/cellToRegion"
<<Writing region 0 with 235940 cells to cellSet region0
<<Writing region 1 with 1398 cells to cellSet region1
<<Writing region 2 with 1587 cells to cellSet region2
<<Writing region 3 with 1567 cells to cellSet region3
<<Writing region 4 with 1664 cells to cellSet region4

Checking patch topology for multiply connected surfaces...
Patch Faces Points Surface topology
wall 8057 4104 ok (non-closed singly connected)
inlets 150 145 ok (non-closed singly connected)
fan1 26 21 ok (non-closed singly connected)
fan2 49 35 ok (non-closed singly connected)
fan3 52 37 ok (non-closed singly connected)
pig1 582 293 ok (closed singly connected)
pig2 618 311 ok (closed singly connected)
pig3 570 287 ok (closed singly connected)
pig4 628 316 ok (closed singly connected)

Checking geometry...
Overall domain bounding box (-200 0 0) (19830 6970 3100)
Mesh (non-empty, non-wedge) directions (1 1 1)
Mesh (non-empty) directions (1 1 1)
Boundary openness (-6.72814e-18 -1.79846e-16 5.96753e-16) OK.
Max cell openness = 2.66659e-16 OK.
Max aspect ratio = 4.59976 OK.
Minimum face area = 1116.39. Maximum face area = 549194. Face area magnitudes OK.
Min volume = 19024.7. Max volume = 1.28777e+08. Total volume = 4.045e+11. Cell volumes OK.
Mesh non-orthogonality Max: 51.359 average: 14.4625
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 0.647568 OK.
Coupled point location match (average 0) OK.

Mesh OK.

End

Hi Thomas,

Boundary condition for p: (not so sure if I got this right)

FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 2 -2 0 0 0 0];

internalField uniform 0;

boundaryField
{
wall
{
type zeroGradient;
}
inlets
{
type fixedValue;
value uniform 0.05;
}
fan1
{
type zeroGradient;
}
fan2
{
type zeroGradient;
}
fan3
{
type zeroGradient;
}
pig1
{
type zeroGradient;
}
pig2
{
type zeroGradient;
}
pig3
{
type zeroGradient;
}
pig4
{
type zeroGradient;
}
}

Sorry for the very long message. Thanks again guys...:)

Hi,

wow, you have a big room:
Total volume = 4.045e+11 m³

Show me your p_rgh. This is more important. p normal is like "calculated" for every boundary.

Bye
Thomas

Yes, it is a very big room.

Here's my p_rgh

FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object p_rgh;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 2 -2 0 0 0 0];

internalField uniform 0;

boundaryField
{
wall
{
type fixedFluxPressure;
rho rhok;
value uniform 0;
}
inlets
{
type fixedFluxPressure;
rho rhok;
value uniform 0;
}
fan1
{
type fixedFluxPressure;
rho rhok;
value uniform 0;
}
fan2
{
type fixedFluxPressure;
rho rhok;
value uniform 0;
}
fan3
{
type fixedFluxPressure;
rho rhok;
value uniform 0;
}
pig1
{
type fixedFluxPressure;
rho rhok;
value uniform 0;
}
pig2
{
type fixedFluxPressure;
rho rhok;
value uniform 0;
}
pig3
{
type fixedFluxPressure;
rho rhok;
value uniform 0;
}
pig4
{
type fixedFluxPressure;
rho rhok;
value uniform 0;
}
}

Also, can I change my p to "calculated" then?

Thanks a lot, Thomas.